Medical system and method of use

ABSTRACT

A medical system and method can used to treat a bone. The system and method can include the preparation of bone cement to be used in the treatment. A non-liquid component and a liquid component can be combined to form a bone cement. A vacuum system can be used to saturate the non-liquid component with the liquid component. The bone cement and/or components can be heated and/or cooled.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/759,573, filed Apr. 13, 2010, which claims the benefit of priorityunder 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/212,622,filed Apr. 14, 2009. This application is related to the following U.S.patent applications Nos.: Ser. No. 11/209,035 filed Aug. 22, 2005, Ser.No. 12/427,531 filed Apr. 21, 2009, Ser. No. 12/345,937 filed Dec. 30,2008, and Ser. No. 12/578,163 filed Oct. 13, 2009; and is related toProvisional Application Nos. 60/842,805 filed Sep. 7, 2006 and60/713,521 filed Sep. 1, 2005. The entire contents of all of the aboveapplications are hereby incorporated by reference and should beconsidered a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present disclosure relate to bone cement injectionsystems, and in some embodiments provide a system for controlling theviscosity of injected bone cement to prevent extravasation.

2. Description of the Related Art

Osteoporotic fractures are prevalent in the elderly, with an annualestimate of 1.5 million fractures in the United States alone. Theseinclude 750,000 vertebral compression fractures (VCFs) and 250,000 hipfractures. The annual cost of osteoporotic fractures in the UnitedStates has been estimated at $13.8 billion. The prevalence of VCFs inwomen age 50 and older has been estimated at 26%. The prevalenceincreases with age, reaching 40% among 80-year-old women. Medicaladvances aimed at slowing or arresting bone loss from aging have notprovided solutions to this problem. Further, the population affectedwill grow steadily as life expectancy increases. Osteoporosis affectsthe entire skeleton but most commonly causes fractures in the spine andhip. Spinal or vertebral fractures also cause other serious sideeffects, with patients suffering from loss of height, deformity andpersistent pain which can significantly impair mobility and quality oflife. Fracture pain usually lasts 4 to 6 weeks, with intense pain at thefracture site. Chronic pain often occurs when one vertebral level isgreatly collapsed or multiple levels are collapsed.

Postmenopausal women are predisposed to fractures, such as in thevertebrae, due to a decrease in bone mineral density that accompaniespostmenopausal osteoporosis. Osteoporosis is a pathologic state thatliterally means “porous bones”. Skeletal bones are made up of a thickcortical shell and a strong inner meshwork, or cancellous bone, ofcollagen, calcium salts and other minerals. Cancellous bone is similarto a honeycomb, with blood vessels and bone marrow in the spaces.Osteoporosis describes a condition of decreased bone mass that leads tofragile bones which are at an increased risk for fractures. In anosteoporosis bone, the sponge-like cancellous bone has pores or voidsthat increase in dimension making the bone very fragile. In young,healthy bone tissue, bone breakdown occurs continually as the result ofosteoclast activity, but the breakdown is balanced by new bone formationby osteoblasts. In an elderly patient, bone resorption can surpass boneformation thus resulting in deterioration of bone density. Osteoporosisoccurs largely without symptoms until a fracture occurs.

Vertebroplasty and kyphoplasty are recently developed techniques fortreating vertebral compression fractures. Percutaneous vertebroplastywas first reported by a French group in 1987 for the treatment ofpainful hemangiomas. In the 1990's, percutaneous vertebroplasty wasextended to indications including osteoporotic vertebral compressionfractures, traumatic compression fractures, and painful vertebralmetastasis. Vertebroplasty is the percutaneous injection of PMMA(polymethylmethacrylate) into a fractured vertebral body via a trocarand cannula. The targeted vertebrae are identified under fluoroscopy. Aneedle is introduced into the vertebrae body under fluoroscopic control,to allow direct visualization. A bilateral transpedicular (through thepedicle of the vertebrae) approach is typical but the procedure can bedone unilaterally. The bilateral transpedicular approach allows for moreuniform PMMA infill of the vertebra.

In a bilateral approach, approximately 1 to 4 ml of PMMA is used on eachside of the vertebra. Since the PMMA needs to be forced into thecancellous bone, the techniques require high pressures and fairly lowviscosity cement. Since the cortical bone of the targeted vertebra mayhave a recent fracture, there is the potential of PMMA leakage. The PMMAcement contains radiopaque materials so that when injected under livefluoroscopy, cement localization and leakage can be observed. Thevisualization of PMMA injection and extravasation are critical to thetechnique—and the physician terminates PMMA injection when leakage isevident. The cement is injected using syringes to allow the physicianmanual control of injection pressure.

Balloon kyphoplasty is a modification of percutaneous vertebroplasty.Balloon kyphoplasty involves a preliminary step comprising thepercutaneous placement of an inflatable balloon tamp in the vertebralbody. Inflation of the balloon creates a cavity in the bone prior tocement injection. In balloon kyphoplasty, the PMMA cement can beinjected at a lower pressure into the collapsed vertebra since a cavityexists, as compared to conventional vertebroplasty. More recently, otherforms of kyphoplasty have been developed in which various tools are usedto create a pathway or cavity into which the bone cement is theninjected.

The principal indications for any form of vertebroplasty areosteoporotic vertebral collapse with debilitating pain. Radiography andcomputed tomography must be performed in the days preceding treatment todetermine the extent of vertebral collapse, the presence of epidural orforaminal stenosis caused by bone fragment retropulsion, the presence ofcortical destruction or fracture and the visibility and degree ofinvolvement of the pedicles.

Leakage of PMMA during vertebroplasty can result in very seriouscomplications including compression of adjacent structures thatnecessitate emergency decompressive surgery. See Groen, R. et al.,“Anatomical and Pathological Considerations in PercutaneousVertebroplasty and Kyphoplasty: A Reappraisal of the Vertebral VenousSystem,” Spine Vol. 29, No. 13, pp 1465-1471, 2004. Leakage orextravasation of PMMA is a critical issue and can be divided intoparavertebral leakage, venous infiltration, epidural leakage andintradiscal leakage. The exothermic reaction of PMMA carries potentialcatastrophic consequences if thermal damage were to extend to the duralsac, cord, and nerve roots. Surgical evacuation of leaked cement in thespinal canal has been reported. It has been found that leakage of PMMAis related to various clinical factors such as the vertebral compressionpattern, and the extent of the cortical fracture, bone mineral density,the interval from injury to operation, the amount of PMMA injected andthe location of the injector tip. In one recent study, close to 50% ofvertebroplasty cases resulted in leakage of PMMA from the vertebralbodies. See Hyun-Woo Do et al., “The Analysis of PolymethylmethacrylateLeakage after Vertebroplasty for Vertebral Body Compression Fractures,”J. of Korean Neurosurg. Soc., Vol. 35, No. 5 (5/2004), pp 478-82,(http://www.jkns.or.kr/htm/abstract.asp?no=0042004086).

Another recent study was directed to the incidence of new VCFs adjacentto the vertebral bodies that were initially treated. Vertebroplastypatients often return with new pain caused by a new vertebral bodyfracture. Leakage of cement into an adjacent disc space duringvertebroplasty increases the risk of a new fracture of adjacentvertebral bodies. See Am. J. Neuroradiol., 2004 February; 25(2):175-80.The study found that 58% of vertebral bodies adjacent to a disc withcement leakage fractured during the follow-up period compared with 12%of vertebral bodies adjacent to a disc without cement leakage.

Another life-threatening complication of vertebroplasty is pulmonaryembolism. See Bernhard, J. et al., “Asymptomatic Diffuse PulmonaryEmbolism Caused by Acrylic Cement: An Unusual Complication ofPercutaneous Vertebroplasty,” Ann. Rheum. Dis., 62:85-86, 2003. Thevapors from PMMA preparation and injection also are cause for concern.See Kirby, B. et al., “Acute Bronchospasm Due to Exposure toPolymethylmethacrylate Vapors During Percutaneous Vertebroplasty,” Am.J. Roentgenol., 180:543-544, 2003.

SUMMARY OF THE INVENTION

There is a general need to provide bone cements and methods for use intreatment of vertebral compression fractures that provide a greaterdegree of control over introduction of cement and that provide betteroutcomes. The present invention meets this need and provides severalother advantages in a novel and nonobvious manner.

Certain embodiments provide bone cement injectors and control systemsthat allow for vertebroplasty procedures that inject cement having asubstantially constant viscosity over an extended cement injectioninterval.

A computer controller can be provided to control cement flow parametersin the injector and energy delivery parameters for selectivelyaccelerating polymerization of bone cement before the cement contactsthe patient's body.

In some embodiments, a system is provided for preparing bone cement. Thesystem can comprise a base and a negative pressure source. The base canbe configured to couple to one or more elongate members, where at leastone of the elongate members can be configured to hold a non-liquidpolymer component in a lumen thereof and to receive a liquid monomercomponent therein for saturation of the non-liquid polymer component bythe liquid monomer component to form a curable bone cement. The negativepressure source can be configured for detachable communication with thebase to draw the liquid monomer component into the non-liquid powdercomponent. Further, the base can include one or more pathways thatcommunicate the lumen of the one or more elongate members and thenegative pressure source.

According to certain embodiments, the system can further include one ormore valves for selectively coupling the negative pressure source toparticular elongate members of the plurality of elongate members.Additionally, a computer controller can be provided to control theplurality of valves, for example, so that the valves can be opened orclosed substantially simultaneously or a selected time intervals. Thecomputer controller may also include a signal system to indicate to auser when to use a particular elongate member in a particular medicaltreatment or when to add liquid monomer component to a particularelongate member.

The system can further include one or more of: a pressure regulator forregulating the pressure of the negative pressure source applied to drawthe liquid polymer into the elongate member; a funnel member forcoupling to an end of the elongate members; a cement ejection mechanismconfigured to couple to one of the elongate members and to eject bonecement from the elongated member into bone; a computer controlleroperatively coupled to the negative pressure source for controlling anegative pressure level applied to each elongate member; a heatingand/or cooling mechanism for respectively heating or cooling theplurality of elongate members and the component or bone cement containedtherein; and a computer controller for controlling either or both of theheating and cooling mechanisms.

In some embodiments, a system for preparing bone cement can include astructure for receiving a plurality of bone cement preparation members.The plurality of bone cement preparation members can be configured toreceive a liquid monomer component and a non-liquid polymer component,the combination of which forms a curable bone cement within theplurality of bone cement preparation members. The structure can includea plurality of channels and a plurality of temperature regulatingassemblies. The plurality of channels can be configured to connect anend of each of the plurality of bone cement preparation members to anegative pressure source. Each of the plurality of temperatureregulating assemblies can be for heating or cooling one of the pluralityof bone cement preparation members. The system may further include acomputer controller for controlling the amount of heat or coolingprovided to the plurality of bone cement preparation members to heat orcool one of the components or the curable bone cement therein.

According to some embodiments each of the temperature regulatingassemblies can comprise a sleeve configured to receive and surround oneof the plurality of bone cement preparation members. The temperatureregulating assemblies can further include a seal to seal an accessopening of the temperature regulating assembly once a bone cementpreparation member has been placed inside the temperature regulatingassembly. An air flow passage can exist between an interior surface ofthe temperature regulating assembly and an exterior surface of the bonecement preparation member. The temperature regulating assembly can havean input and output port in fluid communication with the air flowpassage. A heating or cooling source can generate a hot or cold flow ofgas or liquid to enter the input port and exit the output port.

A method of treating a bone, according to some embodiments can includethe steps of: (a) providing a first liquid component and a secondnon-liquid component of a curable bone cement, (b) heating one or moreof the cement components with a heating system prior to combining thecomponents, wherein the heating system controls the temperature of theone or more components within a range of 1° C. on either side of apredetermined temperature, and (c) applying a partial vacuum to thenon-liquid component to saturate the non-liquid component with theliquid component while maintaining particles of the non-liquid componentin a fixed relationship within a container.

In some embodiments of the method, the non-liquid component is carriedwithin a plurality of elongated sleeves. The heating system can includeat least one of an inductive heating system, a resistive heating system,a light energy heating system, a heated air or gas circulating system,an RF heating system, a microwave heating system, a magnetic heatingsystem, and a heated liquid circulating system. The heating system mayalso be configured to convectively heat the bone cement component, heata member that contains the bone cement component, or heat a structure orspace that is adjacent a member that contains the bone cement component.

According to certain embodiments, a method of treating a patient cancomprise placing each of a plurality of containers of a non-liquidpolymer powder component within a temperature regulating sleeve, placinga container of a liquid monomer component into a temperature regulatingsleeve, heating the liquid monomer component via the temperatureregulating sleeve, and pouring the heated liquid monomer component intoat least two of the containers of non-liquid polymer powder component.The method may further include applying suction to the least twocontainers of non-liquid polymer powder component to saturate the powderwith the liquid so that the non-liquid polymer powder component and theliquid monomer component form a bone cement and thus at least twocontainers contain bone cement and removing a first container of bonecement from the temperature regulating sleeve and ejecting the bonecement into a bone.

In some embodiments, the method may further include the step cooling theat least one other container of bone cement while the first container isused to eject bone cement into the bone. In addition, removing the atleast one other container of bone cement and ejecting the bone cementinto the bone. The method can further include heating the at least oneother container of bone cement after cooling and just prior to removing.In some embodiments, the method can further comprise heating thenon-liquid polymer powder component.

These and other objects of the present invention will become readilyapparent upon further review of the following drawings andspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the invention and to see how it may becarried out in practice, some preferred embodiments are next described,by way of non-limiting examples only, with reference to the accompanyingdrawings, in which like reference characters denote correspondingfeatures consistently throughout similar embodiments in the attacheddrawings.

FIG. 1 is a perspective view of a system for bone cement preparation byvacuum saturation mixing of a polymer powder with a liquid monomer inaccordance with some embodiments.

FIG. 2 is a block diagram of a method for utilizing the system of FIG.1.

FIG. 3 is another bone cement preparation system similar to that of FIG.1.

FIG. 4 is a block diagram of a method for utilizing the system of FIGS.1 and/or 3.

FIG. 5 is a perspective view of another system for bone cementpreparation by vacuum saturation mixing in a plurality of sleeves.

FIG. 6A is a graphical representation of a step involved in certainmethods.

FIG. 6B is a subsequent step of injecting cement into a vertebra.

FIG. 7 is a block diagram of a method for utilizing the system of FIGS.5, 6A and/or 6B.

FIG. 8 is a perspective view of another system for bone cementpreparation by vacuum saturation mixing and pre-heating of the polymerpowder in a sleeve.

FIG. 9 is a perspective view of another system for pre-heating of aliquid monomer.

FIG. 10 is a representative time-viscosity curve of a curable bonecement with and without using a pre-heating system.

FIG. 11 is a block diagram of a method for utilizing the system of FIG.8.

FIG. 12 is a perspective view of another system for bone cementpreparation by vacuum saturation mixing, pre-heating of the polymerpowder, and cooling the cement mixture post-mixing.

FIG. 13 is a block diagram of a method for utilizing the system of FIG.12.

FIG. 14 is another embodiment of a cement injector system withintegrated components.

FIG. 15 is an embodiment of a cement injector system with first andsecond hydraulic assemblies and built-in vacuum saturation components.

FIG. 16 is another embodiment of a cement injector system with first andsecond hydraulic assemblies, built-in vacuum saturation components, anda thermal management system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of understanding the principles of the invention, referencewill now be made to the embodiments illustrated in the drawings and theaccompanying text. As background, a vertebroplasty procedure using abone cement injection system could insert parts of the system(s)described herein through a pedicle of a vertebra, or in a parapedicularapproach, for accessing the osteoporotic cancellous bone. As an example,the bone cement delivery assembly or ejection mechanism shown in U.S.publication no. 2008/0249530 at FIGS. 1-2 and 9-16 could be used. U.S.publication no. 2008/0249530, published Oct. 9, 2008 is incorporatedherein by reference and made a part of this specification, inparticular, FIGS. 1-2 and 9-16 and the accompanying description, such asparagraphs [0055], [0061]-[0063].

The initial aspects of the procedure can be similar to a conventionalpercutaneous vertebroplasty wherein the patient is placed in a proneposition on an operating table. The patient is typically under conscioussedation, although general anesthesia is an alternative. The physicianinjects a local anesthetic (e.g., 1% Lidocaine) into the regionoverlying the targeted pedicle or pedicles as well as the periosteum ofthe pedicle(s). Thereafter, the physician can use a scalpel to make a 1to 5 mm skin incision over each targeted pedicle. Thereafter, anintroducer can be advanced through the pedicle into the anterior regionof the vertebral body, which typically is the region of greatestcompression and fracture. The physician can confirm the introducer pathposterior to the pedicle, through the pedicle and within the vertebralbody by anteroposterior and lateral X-Ray projection fluoroscopic viewsor by other methods. The introduction of infill material as describedbelow can be imaged several times, or continuously, during the treatmentdepending on the imaging method.

DEFINITIONS

“Bone cement, bone fill or fill material, infill material orcomposition” includes its ordinary meaning and is defined as anymaterial for infilling a bone that includes an in-situ hardenablematerial or that can be infused with a hardenable material. The fillmaterial also can include other “fillers” such as filaments,microspheres, powders, granular elements, flakes, chips, tubules and thelike, autograft or allograft materials, as well as other chemicals,pharmacological agents or other bioactive agents.

“Flowable material” includes its ordinary meaning and is defined as amaterial continuum that is unable to withstand a static shear stress andresponds with an irrecoverable flow (a fluid)—unlike an elastic materialor elastomer that responds to shear stress with a recoverabledeformation. Flowable material includes fill material or composites thatinclude a fluid (first) component and an elastic or inelastic material(second) component that responds to stress with a flow, no matter theproportions of the first and second component, and wherein the aboveshear test does not apply to the second component alone.

“Substantially” or “substantial” mean largely but not entirely. Forexample, substantially may mean about 50% to about 99.999%, about 80% toabout 99.999% or about 90% to about 99.999%.

“Vertebroplasty” includes its ordinary meaning and means any procedurewherein fill material is delivered into the interior of a vertebra.

“Osteoplasty” includes its ordinary meaning and means any procedurewherein fill material is delivered into the interior of a bone.

In FIG. 1, a system 100 is illustrated that can be adapted for both bonecement preparation and cement injection in a vertebroplasty procedure.The system 100 can utilize a specialized formulation of a two-part PMMAbone cement, with a non-liquid polymer powder component 105 and a liquidmonomer component 106 (typically carried in vial 108) that post-mixingresults in a curable bone cement 110, described further below.

In one embodiment shown in FIG. 1, the system 100 includes an elongatedcement-carrying structure or sleeve 112. The sleeve 112 can be made of ametal or polymer with a thin wall that has an interior space or channel114. The sleeve 112 can carry a volume of a non-liquid polymer powdercomponent 105 of a bone cement. In some embodiments, the polymer powdercomponent 105 is pre-packed within the sleeve 112. The sleeve 112extends along axis 115 from a proximal end 116, with opening 117 intothe interior space to a distal end 118 with an open termination 120 ofthe interior space 114. The proximal end 116 of the cement-carryingstructure 112 can have a fitting such as a threaded or Luer fitting 122for connecting a pressurization mechanism (described later) to thestructure. The distal end 118 of the structure 112 can also have afitting (e.g., a Luer fitting 124) for connecting a filter and/or vacuumsource to the structure as will be described further below. Thesefittings can also be used for other purposes, such as to cap off theends 116, 118 of the sleeve 112.

Still referring to FIG. 1, the cement-carrying sleeve 112, as shown, hasan elongate configuration. The cross-section of the interior space 114,of some embodiments, can have a diameter of less than 5 mm, less than 4mm or less than 3 mm. The length of the sleeve 112 along axis 115 canrange from about 5 cm to 20 cm, and in one embodiment is 12 cm. Thesleeve 112 can be a transparent biocompatible plastic or other materialto allow viewing of the monomer saturation described below. The volumeof the interior space 114 can carry from about 1 cc to 5 cc of thepolymer powder component 105. In use in a vertebroplasty procedure, inone embodiment, one or more cement-carrying sleeves 112 can be used, asa treatment of a vertebral compression fracture can use from about 2 ccto 8 cc of bone cement.

The sleeve dimensions and cement volumes of a sleeve 112 can allow forrapid heating and/or cooling of the entire cross-section of polymerpowder 105 or bone cement mixture 110 in the sleeve 112. It has beenfound that heating and/or cooling of a column of polymer powder, andparticularly a monomer-saturated powder, can be best accomplished with a“uniform” temperature across the column when the cross section is lessthan about 5 mm. For example, in columns that have a greater crosssectional dimension than about 5 mm, the core of a polymerizing cementmixture may continue to have an unwanted elevated temperature due to theexothermic reaction, while the surface of the column may have a coolertemperature due to proximity to a cooling mechanism positioned about theexterior of the cement-carrying sleeve 112.

As can also be seen in FIG. 1, the system can include a negativepressure source or assembly 130. The negative pressure source 130 can bedetachably coupled to sleeve 112 for suctioning the liquid monomercomponent 106 into and through the non-liquid polymer powder component105 disposed in the sleeve 112. Saturation of the polymer powder 105with the monomer 106 causes the cement to polymerize and set in apost-mixing (or post-saturation) time interval that is described furtherbelow.

In one embodiment, the negative pressure source 130 can have a syringe132 with a lockable plunger assembly 134 that can be withdrawn to applysuction from syringe chamber 135 through channel 136 in body 140 thatcommunicates with open termination 120 in sleeve 112 when connectedtogether by cooperating fittings, such as threads 124 of sleeve 112 andthe receiving threads 138 of the negative pressure source or assembly130. In some embodiments the negative pressure source can include a gascartridge with a negative pressure inside the cartridge, or canalternatively include any other vacuum line, evacuated cartridge or thelike that can produce a vacuum. The negative pressure source or vacuumsource 130 can be detachably coupled to the sleeve 112. This can be forsuctioning the liquid monomer component 106 into and through thenon-liquid polymer powder component 105 disposed in sleeve 112. Thesaturation of the polymer powder 105 with the monomer 106 can thus causethe biomaterial column to begin polymerization and set in post-mixing(or post-saturation) time intervals that are described further below.

The terms wetting and saturating are used interchangeably herein todescribe the process of thoroughly (e.g., completely) exposing thenon-liquid polymer powder component to the liquid monomer component, inother words to unite the two components to thereafter cause apolymerization reaction between at least two portions of thebiomaterials.

In some embodiments, the vacuum source 130 can comprise a syringe. Forexample, the syringe can comprise a 20 cc to 60 cc syringe and moreparticularly a 30 cc syringe. It has been found that a 30 cc syringe canprovide a negative pressure of −500 mmHg or greater. The size of thesyringe and the amount of desired negative pressure of certainembodiments can vary greatly and can depend on many factors. Thesefactors can include the amount of bone cement to be prepared, thecross-section and length of the mixing chamber and the volume anddimensions of the polymer beads. It has been found that high quality,commercially available 20 cc to 60 cc syringes can be actuated toprovide about a negative pressure of −250 mmHg to −750 mmHg which canremain in the syringe for several minutes or indefinitely in someinstances.

In another aspect of the disclosure, a structure 142 carrying a filter144 can be fixedly or detachably connected to body 140 intermediate thecement-carrying sleeve 112 and the negative pressure source 130. In someembodiments, the filter 144 can be a plastic (e.g., high densitypolyethylene) mesh filter having a mean pore dimension of about 0.1 to0.5 microns. The filter 144 of some embodiments can have a mean poredimension of about 0.05 to 10 microns. The filter 144 can be made frommany microporous materials, including plastic, metal, and ceramic.Though a filter is shown, the interface can alternatively be a valve,seal, etc. intermediate the polymer powder or bead component and thevacuum source.

The filter 144 can be configured to allow air extraction from the volumeof compacted polymer powder 105 in sleeve 112 by initial application ofa vacuum from syringe 132. The liquid monomer component 106 whensuctioned through the polymer powder 105 in sleeve 112 creates a higherviscosity mixture akin to a wet sand which will not pass through thefilter 144. By this means, the filter 144 functions to limit any liquidmonomer 106 losses from the saturated mixture, and results in a precisevolume of liquid monomer 106 being drawn by vacuum into the sleeve 112for saturating the polymer powder volume 105.

The filter 144 can advantageously facilitate the operation of the bonecement preparation system 100 according to some embodiments. This isbecause, the filter 144 can allow sufficient negative pressure to passthrough the filter 144 to pull the liquid monomer 106 into thenon-liquid 105 component, while also preventing the liquid monomer fromsimply passing through the sleeve and into the vacuum source. Forexample, in some embodiments, the filter can clog to prevent flow of theliquid monomer. In some embodiments, the cement mixture can clog thefilter to prevent flow of the liquid monomer. In other embodiments, thefilter may swell or polymerize once contacted by the liquid monomer toprevent flow through the filter.

If an insufficient amount of liquid monomer 106 is mixed with thenon-liquid polymer component 105, the mixture will be starved, i.e. itwill have insufficient liquid monomer to begin the curing process in allregions of the mixture. For example, some embodiments of the systemadvantageously produce a de-aerated, non-clumped and homogeneous bonecement admixture. The exact ratio for the monomer and polymer componentscan be provided by the packaging of these components, and the systemdescribed above can help ensure that substantially none of the liquidmonomer escapes the system

In some embodiments, the bone cement precursors can be combined to forma self-curing bone cement as a result of a chemical reaction when apolymer component and liquid monomer component interact, along withactivators and initiators. For example, some embodiments include themixing of a PMMA bone cement that can be provided for a treatment, suchas, treating a vertebral compression fracture, setting an artificialjoint, etc.

In some embodiments, the polymer component 105 is provided in aformulation of bead sizes to cooperate with the monomer volume 106 andnegative pressure from the vacuum source to insure that all surfaces ofthe polymer beads or powder are wetted or saturated. This can be done sothat the admixture does not create a polymerizing volume or other volumethat clogs the intra-bead spaces to prevent monomer 106 migration fromthe superior region of the polymer bead volume 105 to the inferiorregion of the polymer beads.

It can also be important to consider the bead size of the polymercomponent 105 when determining the pore size of the filter 144. If thebead size is too small compared to the pore size, the initialapplication of negative pressure to the mixing chamber can clog thefilter so that the negative pressure cannot draw the needed liquidmonomer into the mixing chamber. This may occur immediately or beforesufficient monomer has been drawn into the mixing chamber. If thisoccurs, it is unlikely that the correct monomer to polymer ratio will beobtained without some further mixing action, such as hand mixing theremaining liquid into the polymer.

The systems and methods described herein can provide many benefits suchas not requiring hand mixing. The system can be faster than mixing byhand, and can minimize or eliminate clumping resulting in more uniformcement. For example, in certain embodiments the system can uniformlycombine the liquid monomer and the non-liquid polymer in less than about20 seconds, in about 10 seconds or in only a few seconds. In addition,the system can contain the fumes created by the chemical reaction whenthe liquid and non-liquid components are combined. For example, thefumes can be contained within the sleeve 112. In some embodiments, atleast a portion of the fumes can be drawn into the vacuum source 130.

In addition, the use of negative pressure to draw the liquid into thenon-liquid can also provide certain benefits. For example, vacuum canremove the air or gas from the non-liquid. This space can be filled withthe liquid to get a more even and uniform saturation. Were the liquid tobe forced into the non-liquid, such as by injecting the liquid, the airis not necessarily removed. Injection can also, in some instances,result in air pockets, clumps, and other areas of non-uniformity. Handmixing can result in similar problems. In some embodiments, the use ofvacuum can substantially, if not completely, remove these problems.

Returning now to FIG. 1, as can be seen, in some embodiments a pressurerelief valve 145 is provided which can be used to limit the amount ofnegative pressure in the syringe 132.

In one embodiment, the body 140 carries a valve indicated at 148 forclosing the channel 136 that runs through the body 140. The valve 148can be used as follows. After closing the valve 148, the lockableplunger assembly 134 is retracted proximally in chamber 135 (asindicated by the arrow in FIG. 1) and locked in this retracted position.With the valve 148 closed, this action provides a selected negativepressure or vacuum inside the chamber 135. Thereafter, with the sleeve112 held in a vertical position, a liquid monomer 106 can be poured intoa funnel 150 and then the valve 148 can be moved to an open position tocreate suction to move the monomer 106 into and through polymer powder105 in the sleeve 112. In this way, the polymer powder 105 can bethoroughly and controllably saturated with the monomer 106 to initiatethe polymerization of the bone cement 110.

The system of FIG. 1 further can include a funnel mechanism 150 forassisting the step of pouring the requisite volume of liquid monomer 106into the open end 117 of the proximal end 116 of the sleeve 112. Asdepicted in FIG. 1, the funnel mechanism 150 can be a funnel memberattachable to sleeve 112. The volume of the funnel can be sized tocontain a volume of monomer 106 required to saturate the volume ofpolymer powder 105 in sleeve 112. The funnel member 150 can befabricated of a clear plastic or other material and can have afluid-tight fitting, such as an o-ring, to couple to sleeve 112.

In one embodiment, the funnel mechanism 150 or the proximal end ofsleeve 112 can carry a filter, seal or valve 155. The filter, seal orvalve 155 can be used for maintaining the polymer powder 105 in thesleeve before use. In some embodiments the filter 155 is a course filterconfigured for maintaining the polymer powder 105 in the sleeve 112while minimizing resistance to flow of liquid monomer 106 through thefilter 155. In one example, the funnel member 150 and filter 155 aredetachably coupled to the proximal end 116 of sleeve 112 after thepolymer powder 105 is packed into the sleeve 112. In another example, adetachable filter 155 can be coupled to the sleeve 112 after the polymerpowder 105 is placed in the sleeve 112. In one embodiment, the filtercan be a high density polyethylene with a mean pore dimension of about25 microns.

In some embodiments, a system 100 for preparing a curable bone cement110 can include an elongated sleeve 112 having an elongated interiorspace 114 carrying less than 5 cc of a non-liquid polymer component 105of a curable bone cement, and a negative pressure source 130 configuredfor detachable communication with the interior space for vacuum infusionof a liquid monomer component 106 into the non-liquid polymer component105. A system for preparing bone cement, according to some embodiments,can include a non-liquid polymer component of a curable bone cementdisposed within an interior space of a plurality of sleeve members 112,and a negative pressure source configured for detachable communicationwith the interior spaces for vacuum infusion of a liquid monomercomponent into the non-liquid polymer component. The various systems forpreparing bone can further include a cement ejection mechanismcoupleable to the sleeve for ejecting the bone cement from the sleeveinto bone, the ejection mechanism selected from the group of, or acombination of: manually actuated piston-like member, hydraulicallyactuated piston, pneumatically actuated piston; a cable-driven piston,and a computer-controlled driver of a piston.

Systems for preparing bone cement, including those described above, caninclude a filter 144 intermediate the sleeve 112 and the negativepressure source 130. In one embodiment, the system can use a swellableporous membrane intermediate the sleeve 112 and the negative pressuresource 130 for preventing any monomer losses from flowing through themembrane. The system can have a filter, seal and/or cap member at one orboth ends of the sleeve for maintaining compacted polymer powder 105 inthe sleeve member 112 for shipping and storage. In some embodiments, thesleeve 112 can be shipped with the funnel 150 and filter 155 containingthe polymer powder 105 at one end and the body 142 and filter 144capping the other end. In other embodiments, the body 140 can beattached to the sleeve for shipping.

In one method illustrated in FIG. 2, the steps of controllablysaturating the polymer powder with monomer can include: (i) placing apolymer powder component under controlled compaction into an interiorspace of a cement-carrying member indicated at 180A; (ii) introducingthe liquid monomer component into a first end of the interior space ofcement-carrying member proximate the polymer powder component indicatedat 180B; (iii) applying a selected negative pressure to the opposing endof the interior space with the negative pressure configured for infusingmonomer through the polymer powder in a selected time interval of lessthan 120 seconds, less that 90 seconds, less than 60 seconds, less than45 seconds or less than 30 seconds, as indicated at 180C; and (iv)utilizing a force application mechanism to eject the saturated bonecement mixture from the cement-carrying member into a patient's bone,indicated at 180D.

FIG. 3 illustrates another system 200 for combining a liquid monomercomponent 106 and a polymer powder component 105. In this system 200,the negative pressure source 130 is similar to that described above. Thecement-carrying member 212 of FIG. 3 can have a syringe body configuredfor coupling to any manually actuated or hydraulically actuated plunger(not shown) for advancing in chamber 214. In one embodiment, thecement-carrying member 212 has a fitting 215 at its proximal end 216 forcoupling to a hydraulic drive mechanism as illustrated in U.S. patentapplication Ser. No. 11/469,769 filed Sep. 1, 2006; Ser. No. 12/024,969filed Feb. 1, 2008; Ser. No. 12/112,477 filed Apr. 30, 2008, 61/067,479,filed on Feb. 28, 2008; 61/067,480, filed on Feb. 28, 2008; 61/124,336,filed on Apr. 16, 2008; 61/190,375 filed Aug. 28, 2008; and 61/124,338filed Apr. 16, 2008, all of which are incorporated by reference hereinin their entirety.

The distal end 218 of member 212 can include a fitting 220 (such as aLuer fitting) for coupling member 212 to structure 142. Structure 142can carry a filter 144 as described above and can be fixedly ordetachably connected to body 140. In FIG. 3, the funnel member 230 canbe detachably coupled to fitting 215 and a seal or an o-ring 232 can beadapted for making a liquid tight fit. A filter 155 also can be providedto maintain the polymer powder in the member 212 as describedpreviously.

In order for a predetermined negative pressure to cause monomer 106 tooptimally saturate the polymer powder 105 within the time intervalsdescribed above, it has been found that several elements can requirecareful control, including (i) the shape and mean dimensions of theconstituent polymer powder(s); (ii) the compaction of the polymer powderin the interior chamber of the sleeve; (iii) the initiators within thepolymer powder; (iv) the height, cross-section, and volume of the columnof polymer powder; and (v) the level of vacuum applied and whether thevacuum level is provided at a constant rate over the saturation intervalor whether the vacuum is provided from an evacuated chamber such thatthe applied negative pressure varies over the saturation interval. Someparameters of the polymer powder 105 are described further below.

In one embodiment, a method of providing an optimized saturationinterval can use an initial pressure developed by an evacuated chamber(e.g., such as a syringe as in FIGS. 1 and 3) of at least 200 mmHgvacuum, at least 250 mmHg vacuum, or at least 350 mmHg vacuum. In theembodiment depicted in FIG. 3, the interior chamber 214 has a diameterof about 16 mm and length of about 60 mm thus providing a volume ofapproximately 12 cc. With a vacuum of about 400 mmHg, the monomer 106will controllably saturate the polymer powder 105 in about 60 seconds.This is using a polymer powder formulation comprising first and secondvolumes of intermixed polymer particles wherein the first volume of PMMAparticles has greater than about 0.5 wt. % benzoyl peroxide (BPO) andthe second volume of PMMA particles comprises less than about 0.5 wt. %BPO, on the basis of the total weight of the polymer powder component.Further, the first volume of PMMA particles has a mean diameter lessthan about 50 μm and the second volume of PMMA particles has a meandiameter greater than about 100 μm. Other polymer powder and monomerformulations can be used and some formulations suitable for the systemare found in U.S. patent application Ser. No. 12/395,532 filed Feb. 27,2009 and Ser. No. 12/578,163 filed Oct. 13, 2009 and incorporated hereinby reference in their entirety and made a part of this specification.

Another method is shown in the block diagram of FIG. 4. Steps ofcontrollably saturating a polymer powder with a liquid monomer caninclude: (i) placing a polymer powder component under controlledcompaction into an interior space of a cement-carrying member indicatedat 150A of FIG. 4; (ii) introducing the liquid monomer component into afirst end of the interior space of cement-carrying member proximate thepolymer powder component as indicated at 150B; (iii) applying a selectednegative pressure to the opposing end of the interior space with thenegative pressure as indicated at 150C; (iv) controlling the volume ofliquid monomer interacting with the polymer with a controlled porosityfilter indicated at 150D; and (v) utilizing a force applicationmechanism to eject the saturated bone cement mixture from thecement-carrying member into a patient's bone, indicated at 150E in FIG.4.

In one embodiment, a system for preparing bone cement, includes aplurality of elongated sleeves having first and second ends; a powdercomponent of a curable bone cement disposed within interiors of thesleeves; and a negative pressure source configured for detachablecoupling to an end of each sleeve for vacuum infusion of a liquidmonomer component into the powder component. The system can furtherinclude a computer controller for controlling a negative pressure levelapplied to each sleeve and/or for selective application of negativepressure level to a particular sleeve over a time interval. In anotherembodiment, a system for preparing bone cement can have an elongatedsleeve having first and second ends, a powder component of a curablebone cement disposed within an interior of the sleeve, and a filterdetachably coupled to an end of the sleeve. The system may furtherinclude a negative pressure source configured for detachable coupling tothe filter for vacuum infusion of a liquid monomer component into thepowder component.

FIG. 5 illustrates another system 300 for preparing a bone cement for avertebroplasty, osteoplasty, or other procedure which system utilizes aplurality of cement-carrying sleeves 112. The sleeves 112 can each carryvarious amounts of polymer powder, such as less than about 5 cc, or lessthan about 2 cc. As shown, a base or stand structure 310 is providedthat has receiving ports 312 for receiving distal ends 118 of aplurality of sleeves 112 or the detachable filter assemblies 142 similarto that of FIG. 1. The base 310 can be configured to receive from 2 to10 or more sleeves 112, and the ports 312 can communicate thoughchannels 315 with a negative pressure source 320. The negative pressuresource 320 can be, for example, a syringe mechanism as in FIG. 1 or avacuum pump such as a hospital vacuum line. A pressure regulator 325 andcontroller 330 can also be provided, as well as, manual orcomputer-controlled valves 332 to close off selected portions ofchannels 315. The pressure regulator 325 can regulate and control thevacuum pressure from the negative pressure source 320 to the basestructure 310 and/or the sleeves 112.

The system 300 and controller 330 can be used or programmed to infusethe monomer 106 into the polymer powder 105 in the sleeves 112. Thesystem and controller can also be used to prepare the sleeves 112 withvolumes of cement at the same time or at selected time intervals. Thecontroller 330 can have a signal system such as aural or visual signalsto indicate when to use a particular sleeve 112, to add monomer to asleeve 112 or the like. In one embodiment, the system 300 includes afunnel assembly 340. As in FIG. 5, the funnel assembly 340 can be aunitary system that can be used when pouring monomer into one or more ofthe sleeves 112. The funnel assembly 340 can connect to the sleeve(s)112 with a slip-fit, friction fit, snap fit, locking fit, etc. Thesystem 300 can allow the physician to control the time at whichdifferent sleeves 112 have a cement volume available at a selectedpolymerization endpoint, and can further allow for controlling the batchsize of cement selected for saturation mixing.

In a method of using the system 300 of FIG. 5, the individual sleeves112 can have monomer 106 saturated into the polymer powder 105 followedby a post-saturation interval of 1 to 3 minutes or more to allow thecement mixture 110 in the sleeve to reach a desired viscosity.Thereafter, in one method as shown in FIG. 6A, a sleeve 112 is insertedinto a cannula 345 previously inserted through a pedicle 348 in vertebra350. A pressure mechanism 360, such as a hydraulic source, and acontroller 365 are then coupled to the sleeve 112. This can be by way ofa proximal fitting 122 or other type of connection. FIG. 6B shows how apiston 370 disposed in the sleeve 112 can be moved distally by a shaft372 or fluid (liquid or gel) flow to thus eject cement mixture 110 intothe interior of the vertebra 350.

In a method corresponding to the block diagram shown in FIG. 7, thesteps of controllably saturating the polymer powder and using the cementmixture can include: (i) placing a PMMA polymer powder component of acurable bone cement under controlled compaction in interior spaces ofabout less than or equal to 5 cc of a plurality of cement-carryingmembers as indicated at 380A of FIG. 7; (ii) introducing the liquidmonomer component into a first end of the interior spaces of thecement-carrying members as indicated at 380B; (iii) utilizing acomputer-controlled application of negative pressure to the opposing endof the interior space to infuse monomer through the polymer powder asindicated at 380C; and (iv) utilizing a force application mechanism toeject the bone cement mixture from the cement-carrying member into apatient's bone, as indicated at 380D.

FIG. 8 illustrates a heat applicator system 400 configured for use inconjunction with the systems 100 and/or 300 of FIGS. 1 and 5. The system400 can be adapted for controlled acceleration of the polymerization ofa monomer-saturated polymer powder in one or more elongatedcement-carrying sleeves 112 that each have a small cross-section asdescribed above. In FIG. 8, the cement-carrying sleeve 112 anddetachable filter-carrying member 142 can be the same as describedpreviously. A funnel member 150 and proximal filter 155 (not shown) canalso be used.

A heater applicator system 400 can include an elongated member 410 witha receiving bore 412 therein dimensioned to receive substantially thelength of the sleeve 112. As depicted in FIG. 8, the heat applicatorutilizes a heating element or emitter 415, such as a resistive heatingelement, with bore 412 therein for conducting heat to the sleeve 112 tothereby heat the polymer powder, but the system can include any heatemitter mechanism within or about an elongate receiving bore 412 that isdimensioned to receive sleeve or sleeves 112. In the embodiment of FIG.8, an outer concentric portion 425 of the member 410 can have aninsulator layer of any thickness necessary to provide thermalinsulation, and can include voids, air gaps, spaces with a partialvacuum, spaces with aerogel insulators, spaces with combination vacuumand aerogels and the like to allow for handling of the member 410 and/oradded safety when in use. FIG. 8 also shows a heating element 415 thatis a PTCR (positive temperature coefficient of resistance) material asis known in the art of constant temperature heaters. Opposing ends ofsides of the heating element 415 are coupled to opposing polarity leads422 a and 422 b of an electrical source 420, and computer controller 430that can include a display 435. While the PTCR resistive heater isdescribed above, a system and method can utilize at least one ofinductive heating, resistive heating, light energy heating, heated airor gas circulation, RF heating, microwave heating, magnetic heating, andheated liquid circulation. The heating system can be configured toconvectively heat, for example, a bone cement component, a member thatcontains a bone cement component, or a structure or space that isadjacent a member that contains a bone cement component.

FIG. 9 illustrates another system that can include a heat applicatorsystem 450 functionally equivalent to that of FIG. 8 except configuredfor heating the monomer component 106 in vial 108 for use in conjunctionwith heated polymer powder 105 as described above. In some embodiments,either or both of the systems of FIGS. 8 and 9 can be used. As depictedin FIG. 9, a member 450 with bore 452 therein utilizes a PTCR resistiveheating element or emitter 455 for conducting heat to a standard vial108 to thereby heat the liquid monomer 106. Also in FIG. 9, an outerconcentric portion 458 has an insulator layer as described above. Again,the scope can include any heat emitter mechanism suitable for heatingthe monomer, and FIG. 9 depicts heating element 455 again coupled toopposing polarity leads 422 a and 422 b of electrical source 420together with controller 430 and display 435.

In a method of using the system of FIG. 8 and optionally the system ofFIG. 9, the steps can include (i) providing liquid and non-liquid cementcomponents of a curable bone cement that post-mixing or post-saturationis characterized by a predetermined first time-viscosity curve at anambient temperature, (ii) heating at least one of the cement componentsprior to mixing or saturation to at least about: 30° C., 32° C., 34° C.,36° C., 38° C., 40° C., 42° C., 44° C., 46° C., 48° C. or 50° C., and(iii) mixing the cement components wherein the at least one heatedcement component provides a cement mixture characterized by an alteredsecond time-viscosity curve. The system can heat the polymer powder 105in sleeve 112 and/or the monomer 106 in vial 108 to the desiredtemperature(s) within one to five minutes, and a display can indicatethe temperature or a time to initiate monomer-polymer saturation withthe systems described above.

In another aspect of a method, the pre-heating of the polymer powderand/or the monomer can provide an altered or second time-viscosity curvethat is characterized by the mixture reaching a viscosity of at least1000 Pa·s in less than 2 minutes post-mixing, or by the mixture reachinga viscosity of at least 1500 Pa·s in less than 3 minutes as depicted inFIG. 10. In FIG. 10, a first time-viscosity curve 485 is shown for acement mixture that is saturated or mixed at about 20° C. ambienttemperature. FIG. 10 shows an altered or second time-viscosity curve485′ for the same cement mixture when the polymer powder is pre-heatedto have a uniform temperature of about 40° C. prior to saturation withmonomer. The time-viscosity curves 485 and 485′ are approximated from apolymer powder 105 heated to 40° C., with the polymer powder and monomerformulations found in U.S. patent application Ser. No. 12/395,532 filedFeb. 27, 2009.

Another method of preparing a cement can include the steps of (a)providing a first liquid component and a second non-liquid component ofa curable bone cement; (b) placing the cement components, prior tomixing, in a system that controls the temperature of the first andsecond components within a range of 2° C. or 1° C. on either side of apredetermined temperature; and (c) exposing the non-liquid component tothe liquid component while maintaining particles of the non-liquidcomponent in a fixed relationship within a container. It has been foundthat widely varying ambient temperatures in operating rooms, and cementcomponent storage rooms in hospitals, contribute to high variability intime-viscosity curves of mixed cements. The heating systems describedherein can be used to help ensure that cement precursors are at apre-selected temperature just prior to saturation mixing, such as withina small range of variability, for example 2° C. or 1° C.

A method is shown in the block diagram of FIG. 11, wherein the steps ofcontrollably saturating the polymer powder can include: (i) placing apolymer powder component of a curable bone cement under controlledcompaction in interior spaces of a plurality of cement-carrying membersas indicated at 480A of FIG. 11; (ii) pre-heating the powder componentto a pre-determined temperature in the range of 30° C. to 60° C. and/orpre-heating the monomer to a similar temperature; (iii) mixing a monomercomponent with the polymer component; and; (iv) utilizing a forceapplication mechanism to eject the bone cement mixture from thecement-carrying member into a patient's bone, as indicated at 480D ofFIG. 11.

FIG. 12 illustrates an embodiment of a system 500A for preparing acurable bone cement within sleeve 112 as described above and having areceiving structure 510 for receiving sleeve 112. Receiving structure510 can include both a heating mechanism and a cooling mechanism thatare computer controlled. This can allow for complete temperaturemanagement of the bone cement prior to mixing and post-mixing thusallowing the physician to have a pre-determined cement viscosity andalso to provide a very long time interval during which one or morecement-carrying sleeves 112 may be utilized.

The system of FIG. 12 illustrates elongated member 510 with a receivingbore 512 therein that is dimensioned to receive substantially the lengthof the sleeve 112. Resilient seals or collars 514 a and 514 b aredimensioned to fit closely around the exterior of sleeve 112. In oneembodiment depicted in FIG. 12, the heat applicator utilizes aninductive coil 515 around bore 512 that is coupled to RF source 520,computer controller 525 and display 530. The coil 515 can be actuated toinductively heat the sleeve 112, where the sleeve 112 is fabricated of amaterial that can be inductively heated, such as a biocompatiblestainless steel (e.g., SS316). It should appreciated that a PTCRresistive heater as described above can be used, as can other heatingdevices and methods, such as resistive heating, light energy heating,heated air or gas circulation, microwave heating, magnetic heating, orheated liquid circulation.

In some embodiments, the sleeve 112 is heated with light energy (e.g.LEDs) or an inductive coil 515. In addition, a free space 532 around thesleeve 112 in bore 512 can be used with a cooling mechanism, such as toreceive flow of a cooling fluid from a cooling fluid source 540. In oneembodiment, the cooling fluid can be a cooling gas from source 540 andpressure regulator 545, such as a liquid CO₂, liquid nitrogen or thelike.

In FIG. 12, the cooling fluid can flow into inflow port 546communicating with space 532 and then out outflow port 548. An outerconcentric portion 550 of structure 510 can also use an insulator layeras described above.

A heating system can be used to pre-heat the cement precursors asdescribed above. The system can also include a negative pressure source320 and a regulator 325 coupleable to the sleeve 112 and filterstructure 142 as described previously to saturate the polymer powder insleeve 112 with the monomer. Post-saturation, the system and controllercan be programmed to maintain a selected temperature in thecement-carrying sleeve 112. For a selected cooled temperature, thesystem and controller can modulate the flow of a cooling gas or fluiduntil the sleeve 112 is needed for use. At that time, the heating systemcan optionally be used to heat the cement in sleeve 112 to ambient roomtemperature or another selected temperature for injection into bone.

In general, the bone cement and system of FIG. 12 can include: (i) aliquid monomer component 106 and a non-liquid polymer component 105 of acurable bone cement, the polymer component carried in interior space(s)of one or a plurality of elongated cement-carrying members, (ii) astructure for receiving one or a plurality of the cement-carryingmembers; (iii) a heating assembly on the structure for applying heat tothe interior space(s) of one or the plurality of elongatedcement-carrying members, and (iv) a cooling assembly on the structurefor subtracting heat from the interior space(s) of one or the pluralityof elongated cement-carrying members.

The block diagram of FIG. 13 describes a method wherein the steps ofpreparing and using a bone cement can include: (i) placing a polymerpowder component of a curable bone cement under controlled compaction inthe interior space of at least one cement-carrying member as indicatedat 580A of FIG. 11; (ii) pre-heating the powder component to apre-determined temperature in the range of 30° C. to 60° C. and/orpre-heating the monomer to a similar temperature; (iii) mixing a monomercomponent with the polymer component; (iv) utilizing acomputer-controlled cooling system to cool the bone cement in thecement-carrying member(s) as indicated at 580D of FIG. 13; and (v)utilizing a force application mechanism to eject the bone cement mixturefrom cement-carrying member(s) into a patient's bone, as indicated at580E of FIG. 13. The method can also include the step of heating thecement after the cooling step, but before injection into bone toaccelerate the polymerization of the cement mixture.

FIG. 14 illustrates an integrated system 500B that includes a base orstand assembly 585 with a plurality of structures 510 and heaters 515,such as inductive heaters similar to that of FIG. 12, that can receive aplurality of cement-carrying members 112. The plurality of structures510 can range from 2 to 10 or more. The system 500B further includes aheating source 520, a computer controller 525, a display 530, negativepressure source 320 and regulator 325, a cooling gas source 540 and apressure regulator 545 similar to that shown in the embodiment of FIG.12. The system can include a heating assembly 450 for pre-heatingmonomer 106 in vial 108 as shown in FIG. 9. In some embodiments, theheating source 520 can be an RF heating source.

In use, it can be understood that the physician can select any number ofcement-carrying structures 112 for a procedure, and then pre-heat andmix the cement, and then controllably cool the cement until needed inthe course of a procedure. The system is particularly useful in that allcement can be mixed in advance, and independent of how many delays inthe procedure or the length of the procedure, bone cement of a known,controlled viscosity can always be readily available.

In one embodiment as in FIG. 14, the display 530 can include indicators588 of the temperature of each cement-carrying sleeve 112, and thecontroller can also include a hydraulic drive mechanism 590 as describedin U.S. patent application Ser. No. 12/345,937 filed Dec. 30, 2008.

A system for preparing bone cement similar to FIG. 14 can include: (i) aliquid monomer component and a non-liquid polymer component of a curablebone cement, the polymer component carried in interior spaces of aplurality of elongated cement-carrying members; (ii) a structure forreceiving a plurality of the members; (iii) a negative pressure sourceconfigured for detachable communication with the structure and theinterior spaces of the plurality of the members; and (iv) thermalmanagement comprising computer controllable heating and cooling systemsfor controlling the temperature and viscosity of the bone cement priorto injection into bone.

FIG. 15 illustrates a system 600 for use with a bone cement injectorsystem, similar to those described in U.S. patent application Ser. No.12/345,937 filed Dec. 30, 2008 and incorporated herein by reference, inparticular, FIGS. 4-6 and the accompanying description, such asparagraphs [0051]-[0061] in the application as filed. The bone cementinjector system can include first and second hydraulic assemblies 610Aand 610B together with a controller and energy source in a singleintegrated station or box 605. In use, the first and second hydraulicassemblies 610A and 610B can allow for rapid switching between cementsyringes in cases where multiple syringes of cement are injected. In aconventional hydraulic unit, it may require from 20 seconds to 2 minutesto retract a screw-driven mechanical drive mechanism that moves within ahydraulic cylinder. Thus, by providing two hydraulic assemblies, theflexibility of the system can be increased and the time required for asurgical procedure can be reduced.

System 600 of FIG. 15 can include an integrated station or control box605 for use with the injectors as also described in U.S. patentapplication Ser. No. 12/345,937. As shown, a negative pressure source320 and controller 325 can be built into the hydraulic controller box605. The negative pressure source 320 is configured to receive at leastone cement-carrying member or syringe 212 as in FIG. 3 for vacuumsaturation of the polymer powder 105.

FIG. 16 illustrates a system 700 for use with the a plurality ofcement-carrying sleeves 112 as in FIG. 14, and includes first and secondhydraulic assemblies 610A and 610B together with a controller, andthermal management system of FIG. 14 all integrated into a single unit705. In all other respects, the integrated system 700 of FIG. 14operates as described previously.

In some embodiments, the systems utilize computer algorithms that allowfor temperature management of cement parameters to allow for selectionof different cement viscosities across the different cement-carryingsleeves 112 by simple selection and actuation of a button. For example,higher and lower viscosities can be selected on demand.

In another embodiment, the hydraulic injection system can use a gel,such as a hydraulic fluid, which prevents loss or leakage of fluidduring storage, shipping, sterilization and the like.

The above description is intended to be illustrative and not exhaustive.In addition, particular characteristics, features, dimensions and thelike are presented in the dependent claims. These can be combined invarious embodiments and fall within the scope of the disclosure. Itshould be understood that various additional embodiments encompass thedependent claims as if they were alternatively written in a multipledependent claim format with reference to other independent claims.Specific characteristics and features of the embodiments of the systemsand methods are described in relation to some figures and not in others,and this is for convenience only. While certain principles have beenmade clear in the exemplary descriptions and combinations, it will beobvious to those skilled in the art that modifications may be utilizedin practice which are particularly adapted to specific environments andoperative requirements without departing from the principles espousedherein.

Of course, the foregoing description is that of certain features,aspects and advantages, to which various changes and modifications canbe made without departing from the spirit and scope of the disclosure.Moreover, the bone treatment systems and methods need not feature all ofthe objects, advantages, features and aspects discussed above. Thus, forexample, those skill in the art will recognize that the systems andmethods can be embodied or carried out in a manner that achieves oroptimizes one advantage or a group of advantages as taught hereinwithout necessarily achieving other objects or advantages as may betaught or suggested herein. In addition, while a number of variationshave been shown and described in detail, other modifications and methodsof use, which are within the scope of the disclosure, will be readilyapparent to those of skill in the art based upon this disclosure. It iscontemplated that various combinations or subcombinations of thesespecific features and aspects of embodiments may be made and still fallwithin the scope of the disclosure. Accordingly, it should be understoodthat various features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the discussed bone treatment systems and methods.

1. (canceled)
 2. A method of treating a bone comprising the steps of:(a) providing a first liquid component and a second non-liquid componentof a curable bone cement; (b) controlling the temperature of one or moreof the bone cement components with a control system prior to combiningthe components within a selected narrow temperature range; and (c)applying a partial vacuum to the non-liquid component to saturate thenon-liquid component with the liquid component while maintainingparticles of the non-liquid component in a fixed relationship within acontainer.
 3. The method of claim 2, wherein the non-liquid component iscarried within at least one elongated member.
 4. The method of claim 3,wherein each elongated member carries the non-liquid component in aspace having a cross-section adapted for rapid thermal conduction acrosssaid cross section.
 5. The method of claim 2, wherein the control systemcomprises at least one of an inductive heating system, a resistiveheating system, a light energy heating system, a heated air or gascirculating system, an RF heating system, a microwave heating system, amagnetic heating system, and a heated liquid circulating system.
 6. Themethod of claim 2, wherein the control system is configured toconvectively heat the bone cement component, heat a member that containsthe bone cement component, or heat a structure or space that is adjacenta member that contains the bone cement component.
 7. The method of claim2 wherein controlling the temperature is performed by a computer controlsystem.
 8. The method of claim 2, controlling the temperature comprisesplacing the components into temperature regulating members.
 9. Themethod of claim 2, wherein applying a partial vacuum to the non-liquidcomponent to saturate the non-liquid component with the liquid componentforms a bone cement.
 10. The method of claim 9, further comprisinginjecting the bone cement into a site in or proximate to a bone.
 11. Amethod of treating a patient comprising: placing at least one containerof a non-liquid polymer powder component within a temperature regulatingmember; placing a container of a liquid monomer component into atemperature regulating member; heating the liquid monomer component viathe temperature regulating member; pouring the heated liquid monomercomponent into the at least one container of the non-liquid polymerpowder component; applying suction to the least one containers of thenon-liquid polymer powder component to saturate the powder with theliquid so that the non-liquid polymer powder component and the liquidmonomer component form a bone cement and thus at least one container ofbone cement; and removing the at least one container of bone cement fromthe temperature regulating member and injecting the bone cement into asite in or proximate to a bone.
 12. The method of claim 11, furthercomprising cooling the at least one container of bone cement.
 13. Themethod of claim 12, further comprising injecting bone cement from atleast a second container into a site in or proximate to the bone. 14.The method of claim 11, wherein the non-liquid polymer powder componentis carried within at least one elongated member.
 15. The method of claim14, wherein each elongated member carries the non-liquid polymer powdercomponent in a space having a cross-section adapted for rapid thermalconduction across said cross section.
 16. The method of claim 11,wherein the temperature regulating member comprises at least one of aninductive heating system, a resistive heating system, a light energyheating system, a heated air or gas circulating system, an RF heatingsystem, a microwave heating system, a magnetic heating system, and aheated liquid circulating system.
 17. The method of claim 11, whereinthe temperature regulating member is configured to convectively heat theliquid monomer component, heat a member that contains the liquid monomercomponent, or heat a structure or space that is adjacent a member thatcontains the liquid monomer component.
 18. The method of claim 11wherein heating the liquid monomer component is controlled by a computercontrol system.